472 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



under the title of a company, for the cutting of tlie Isthmus of Ilolhind, i(y 

 establish a canal joining Amsterdam and the North Sea by a direct route, 

 while at the same time the Dutch government has undertaken to establish 

 another navigable route from Rotterdam to the sea. 



A new project is presented which, if realized, will complete a series of 

 maratime communications in the north of Europe. It is proposed to estab- 

 lish a canal, navigable for ships of war and commerce, between the North 

 •Sea and the Baltic, to avoid making the passage of the Danish Islands, 

 This project, often thought of, is now very seriously considered. 



Finally, they are speaking of cutting one other isthmus, and this time it 

 is Spain which has the honor. It is proposed to pierce the Spanish isth- 

 mus in such a way that Gibralter will be an island. The canal is to start 

 from Trafalgar and end at xindalusia. The canal which would cost hardly 

 a hundred millions of francs, has for its object to prevent more than 4,000 

 vessels every year from " lying to " before the strait of Gibralter without 

 power to get out. 



Heat, 



The regular discussion was opened by Dr. Kowcll, with ren:iarks upon 

 heat as a mode of motion. 



The Chairman remarked that the discussion of the abstract question of 

 "heat, as a mode of motion," opened a very wide field. The subject has 

 been fully and clearly presented in the work of Prof. Tyndall, of the Ro^^al 

 Institution, London. To understand why heat cannot be matter, but must 

 be the eft'ect of the undulating motion of a very attenuated, imponderable 

 fluid, it is necessary to study the phenomena known as the polarization of 

 heat. There are many phenomena connected with liglit which have their 

 counterpart in the action of heat. That light is not the result of the emis- 

 sion of matter, has been as absolutely settled as any other question upon 

 which experiment can give us positive knowledge. The plain inference in 

 the absence of direct proof would be that light is a mode of motion. But 

 there are many phenomena which can be repeated at pleasure, confirming 

 the view that the effects of heat and light are the result not only of motion 

 but of a particular kind of motion which seems to be exhibited only in con- 

 nection with them and actinism. The chair suggested the propriety of 

 confining our discussion at present to the best modes of generating heat, 

 and of applying it to useful ends. It should be stated however tl>at this 

 association is always desirous of witnessing new experiments which may 

 illustrate the operation of any physical law. 



Mr. Fisher said: "According to the new theory of heat, which has been 

 stated by Dr. Rowell, it niiakes little diflerence what agent it acts upon, 

 whether water, ether, air, gas or steam. But though the power evoked 

 may be the same, there may be a difference in the proportion of it which is 

 utilized, and there is a difierence in the cost of material and in the dura- 

 bility of metal under different temperatures. Steam boilers last sixty years 

 in cases of slow combustion and low pressure, six years in other cases, and 

 six months if the firing is violent and the water spaces narrow. Air 

 engines last for months, or weeks, or days, according to the fii'ing. Ether, 

 carbonic acid, sulphuret of carbon, and such agents, are costly and unplea- 



